Features: This product is for use only in House of Kolor Ko-Seal II UC & UFC Klears Due to Its unique chemistry KU150 should never be substituted with other brand catalysts This product must be mixed with other products before use This product must be mixed with other products before use. KU150 is a multi-purpose catalyst for urethane finishes. It is used in the KO-SEAL? II Primer Sealers UC35 and UFC35 Kosmic Klears. NOTE: Monitors vary - onscreen colors are for general color reference only.